JP3339148B2 - Cordless equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cordless device applied to a product such as a jar. That is, the present invention relates to a device which can be used even when a commercial AC power supply is connected, and which can be used in a cordless state where a commercial AC power supply is not connected.

[0002]

2. Description of the Related Art Conventionally used cordless devices include:
The configuration is as shown in FIG. That is,
100V commercial AC power supply 1
To a low voltage of about 10 V, to dc by the rectifier circuit 3, to charge the storage element 4 composed of a secondary battery or a large-capacity capacitor, and to drive the load 6 connected via the switch 5. Is what it is.

With the above configuration, when the switch 5 is closed and the load 6 is operated while the commercial AC power supply 1 is connected, a current passing from the commercial AC power supply 1 through the transformer 2 and the rectifier circuit 3 is also supplied to the load 6. , Load 6 can be used in the usual manner with a cord. When the switch 6 is closed and the load 6 is operated while the commercial AC power supply 1 is disconnected, the charge stored in the storage element 4 is supplied to the load 6 and the load 6 can be used in a cordless state. Things.

[0004]

However, in the above-mentioned conventional configuration, since the transformer 2 is used, the equipment is large, heavy, and expensive. Further, when the commercial AC power supply 1 is connected, the transformer 2 and the rectifier circuit 3 need to supply a current to the load 6 and supply a charging current to the power storage element 4 at the same time. When the battery is completely discharged, the load 6 cannot be driven until the charging is advanced. In the cordless state, the voltage supplied to the load 6 becomes equal to the voltage of the storage element 4, so that the charge stored in the storage element 4 is insufficient due to the direct influence of the fluctuation of the terminal voltage of the storage element 4. In such a case, the driving of the load 6 cannot be sufficiently performed.

An object of the present invention is to provide a cordless device capable of driving a load in a cordless state by using a transformer without using a transformer. Is the primary purpose. A second object of the present invention is to provide a cordless device capable of sufficiently driving a load irrespective of the progress of charging of a storage element. It is a third or fourth object of the present invention to provide a cordless device having a reduced charging time. A fifth object of the present invention is to provide a cordless device that can operate the device even during a power failure. Still another object of the present invention is to provide a highly reliable cordless device.

[0006]

A first means of the present invention for achieving the first object is to provide a current supply circuit comprising a detachable commercial AC power supply and a first load, and a current supply circuit comprising the same. A rectifier circuit connected to the rectifier circuit, a series circuit of a first transistor and a second transistor connected to the output of the rectifier circuit, a first reverse conducting diode connected between the collector and the emitter of the first transistor, A second reverse conducting diode connected between the collector and the emitter of the second transistor, a series circuit of a choke coil and a storage element connected between the collector and the emitter of the first transistor, A control circuit for controlling on / off of one transistor and the second transistor, and a control circuit between a connection point of the choke coil and the storage element and a collector of the second transistor. It is an cordless device having a series circuit of a switch for operating the user and a second load connected.

A second means for achieving the second object of the present invention, in addition to the structure of the first means of the present invention, detects a voltage across a series circuit of a second load and a switch. It has voltage detection means for outputting this detection voltage to the control circuit, and voltage setting means operated by the user, and when the commercial AC power supply is connected, the control circuit controls the conduction ratio of the second transistor. Thus, the cordless device controls the output voltage of the voltage detection means and the output voltage of the voltage setting means to be equal.

A third means of the present invention for achieving the third object has a voltage source for generating a constant voltage and a second switch in addition to the configuration of the second means of the present invention, When the switch is turned off while the AC power supply is connected, the voltage setting means is a cordless device that outputs the voltage on the voltage source side to the control circuit.

A fourth means of the present invention for achieving the fourth object has a third switch connected to a voltage detecting means in addition to the constitution of the second means or the third means of the present invention. The voltage detection means is a cordless device that detects the voltage across the second load when the switch is on and detects the output voltage of the rectifier circuit when the switch is off.

According to a fifth aspect of the present invention for achieving the fifth object, in addition to the configuration of the second, third, or fourth means of the present invention, a commercial AC power supply is connected. And a control circuit that controls the conduction ratio of the first transistor when the commercial AC power supply is not connected, so that the output voltage of the voltage detection means and the output voltage of the voltage setting means are provided. And a cordless device that controls so as to be equal.

According to a sixth aspect of the present invention for achieving the sixth object, in addition to the configuration of the second means, the third means, the fourth means or the fifth means of the present invention, A cordless device that has a duty ratio limiting means for limiting the duty ratio of one transistor, and wherein the control circuit controls the first transistor so as not to exceed a predetermined duty ratio.

[0012]

According to the first means of the present invention, a first load connected in series to a commercial AC power supply drops the power supply voltage to an appropriate value, thereby eliminating the need for a transformer. On / off control of the second transistor according to the status of whether the commercial power supply is connected or not, operating the hot water supply motor which is the second load and pouring hot water in a state with a cord or in a cordless state It works to be able to do it.

The second means of the present invention is characterized in that the control circuit receives the working voltage set in the voltage setting means and the voltage across the second load detected by the voltage detecting means, and Even if the terminal voltage changes, it acts to adjust the voltage of the hot water supply motor (second load) to the working voltage set in the voltage setting means. That is, the user can adjust the hot water supply speed to a desired value by the voltage setting means.

[0014] The third means of the present invention particularly works to increase the charging speed of the storage element. In other words, the control circuit operates as a step-down chopper when the commercial AC power supply is connected, and the voltage setting at both ends of the second load can be increased by the voltage source that generates a constant voltage and the second switch. The power supplied from the coil increases, and the charging current can be higher than the current supplied by the current supply circuit.

According to a fourth aspect of the present invention, the control circuit comprises:
Since the voltage between both ends of the series circuit of the first transistor and the second transistor is controlled to be the voltage of the voltage source that generates a constant voltage, especially when the charging voltage of the storage element is low, the second Of the transistor becomes extremely large, the charging current of the power storage element becomes extremely large, and the time until the charging is completed can be further shortened.

According to a fifth aspect of the present invention, when the detecting means detects a power failure of the commercial AC power supply, the control circuit determines the voltage across the second load detected by the voltage detecting means. The second load can be driven even during a power outage by controlling the conduction ratio of the first transistor so that the voltage is set to the voltage set as described above.

According to a sixth aspect of the present invention, the control circuit operates to limit the duty ratio of the first transistor to less than 1 in response to the information of the duty ratio limiting means. Therefore, a highly reliable cordless device capable of preventing element destruction can be realized.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the first means of the present invention will be described below with reference to FIG. This embodiment relates to a jar pot capable of supplying cordless hot water. The commercial AC power supply 21 is detachably connected to a current supply circuit 25 by a magnet type detachable cord 22. The current supply circuit 25 includes a commercial AC power supply 21 connected via the cord 22 and a first load 24 connected in series to the commercial AC power supply 21. As the first load 24, a warming heater 23 for maintaining the temperature of the hot water housed in a warming tube (not shown) is used in the present embodiment. Current supply circuit 25
Is connected via a rectifier circuit 26 to a series circuit of a first transistor 27 and a second transistor 28 connected to the output of the rectifier circuit 26. In this embodiment, NPN transistors are used as the first transistor 27 and the second transistor 28. A first reverse conducting diode 29 is provided between the collector and the emitter of the first transistor 27, a second reverse conducting diode 30 is provided between the collector and the emitter of the second transistor 28, A series circuit of a choke coil 31 and a storage element 32 is connected between the collector and the emitter of the transistor 27. Further, a series circuit of a hot water supply motor 33 and a switch 36 constituting a second load is connected between a connection point between the choke coil 31 and the storage element 32 and a collector of the second transistor 28. Further, the bases of the first transistor 27 and the second transistor 28 are connected to the control circuit 35, and are turned on and off by the control circuit 35.

The operation of this embodiment will be described below.
In a state where the commercial AC power supply 21 is connected by the cord 22, a current limited by the first load 24 constituted by the heat retaining heater 23 is supplied from the commercial AC power supply 21 through the cord 22. The output of the current supply circuit 25 is supplied from a full-wave rectifier circuit 26 to a switch 36.
Is supplied to a series circuit of a hot-water supply motor 33 and a power storage element 32 which constitute a second load 34 via the power supply. Therefore, when the user turns on the switch 36, the hot water supply motor 33 operates to supply hot water kept in the heat retaining tube to the outside,
At the same time, a charging current flows through the storage element 32.

When it is not necessary to supply hot water, the switch 36 is held in the off state. In this state, when the charging of the storage element 32 is not completed, the control circuit 35 supplies the base current to the second transistor 28. Rectifier circuit 2
The current also flows from the output of 6 to the second transistor 28,
This is to charge the storage element 32 through the choke coil 31. At this time, even if the control circuit 35 turns off the second transistor 28, the magnetic energy stored in the choke coil 31 is transferred to the first reverse conducting diode 29.
Flows through the storage element 32 and the first transistor 2
No reverse voltage is applied between the collector and the emitter of No. 7.

As described above, when the power supply circuit 25 is connected to the commercial AC power supply 21 by the cord 22, the current from the current supply circuit 25 is supplied to the second load 34 and the electric storage element 32.

Next, the operation when the detachable cord 22 is removed and the commercial AC power supply 21 is not connected will be described. When the cord 22 is removed, a switch provided at a connection portion of the cord 22 (not shown) operates, and the control circuit 35 detects that the cordless state has been entered, and turns on and off the first transistor 27 at about 30 kHz. start. When the first transistor 27 is on, a current flows from the storage element 32 through the choke coil 31 and the first transistor 27. After a predetermined period of time (for example, about 20 μs when the conduction ratio is 0.6), when the first transistor 27 is turned off by the control circuit 35, the current flowing through the choke coil 31 is stored therein. It does not suddenly become zero due to magnetic energy,
The power is supplied to the second load 34 through the second reverse conducting diode 30. Thus, the stored energy of the choke coil 31 gradually decreases. However, when the predetermined time has elapsed and the control circuit 35 turns on the first transistor 27 again,
A current flows again through the storage element 32 and the choke coil 31, and magnetic energy is stored. Therefore, the second load 34 includes
The current is continuously supplied from the choke coil 31.

In this way, even in a cordless state where the commercial AC power supply 21 is not connected, since the voltage is supplied to the hot water supply motor 33 constituting the second load 34, if the user turns on the switch 36, The hot water that is kept warm in the heat retaining cylinder can be supplied.

As described above, in the present embodiment, the control circuit 35 controls the first transistor 27 and the second transistor 28 on and off in accordance with the status of whether the cord 22 is connected or not. The hot water can be supplied by operating the second load 24, that is, the hot water supply motor 33, regardless of whether the cord 22 is connected or the cord 22 is removed.

In particular, in the present embodiment, the heater 23 required for a normal jar pot is connected to the first load 24.
Since the voltage of the commercial AC power supply 21 is lowered to an appropriate value, it is not necessary to separately provide a transformer having a large weight, price and volume such as a transformer. While charging, a slight current flows through the heater 23,
Since the heater 23 has a small capacity, it has no particular effect.

There is no problem if a high-power heater for boiling water is used as the first load 24, but in such a case, the capacity of the power storage element 32, the first transistor 27
Second transistor 28, first diode 29, second diode 30, choke coil 31, storage element 32
Need to be increased.

Next, an embodiment of the second means of the present invention will be described with reference to FIG. In this embodiment, in addition to the configuration of FIG. 1, a voltage detecting means for detecting a voltage across the second load 34 and generating an output corresponding thereto at both ends of a series circuit of the second load 34 and the switch 36. 38 are connected. The output of the voltage detecting means 38 is connected to a control circuit 41 which controls the first transistor 27 and the second transistor 28. The control circuit 41
Is connected to a voltage setting means 39 having a variable resistor 40 adjustable by the user.

The operation of this embodiment will be described below.
When the switch 36 is off, the operation is the same as that of the first embodiment of the present invention, and the description is omitted.

With the commercial AC power supply 21 connected by the cord 22, the user operates the switch 36 to turn it on, and the voltage setting means 39 constituted by the variable resistor 40 is rotated to turn on the voltage setting means 39. If the voltage is set to an appropriate voltage, the electric current is supplied to the hot water supply motor 33 constituting the second load 34. That is, the hot water kept warm in the heat retaining cylinder can be supplied to the outside.

When the control circuit 41 determines that the output of the voltage setting means 39 set by the user is larger than the output of the voltage detection means 38 while the switch 36 is turned on, The conduction ratio of transistor 28,
That is, it works so as to lower the ratio of the on-time. As a result, the ratio of the current supplied from the current supply circuit 25 that is bypassed by the second transistor 28 decreases, and the current supplied to the hot water supply motor 33 increases. Therefore, the voltage at both ends of the second load 34 also increases, and the supply voltage of the hot water supply motor 33 also increases. When it is determined that the output of the voltage setting means 39 set by the user is smaller than the output of the voltage detecting means 38, the operation is performed to increase the conduction ratio of the second transistor 28, contrary to the above. Things. As a result, the ratio of the current supplied from current supply circuit 25 that is bypassed by second transistor 28 increases, and hot water supply motor 33
Is reduced. As a result, the voltage across the second load 34 also decreases, and the hot water supply motor 33
Is also reduced. That is,
The control circuit 41 performs negative feedback control on the voltage across the second load 34, and controls the voltage as set in the voltage setting means 39. For this reason, even if the terminal voltage of the storage element 32 changes, the voltage of the hot water supply motor 33 can be freely adjusted by the user, and the user can adjust the hot water supply speed to a desired value. .

Next, a hot water supply operation is performed in a cordless state.
Will be described. In this state, the control circuit
Reference numeral 41 denotes the first transformer as described in the above embodiment.
The on / off control of the register 27 is about 30 kHz.
It operates as a loose boost chopper. Follow
The voltage supplied to the second load 34 is
1 is the average value of the magnetic energy stored in
You. For this reason, the power of the voltage setting means 39 set by the user is set.
The control circuit 41 turns off the first transistor 27 according to the voltage.
When the ratio between the power-on and the power-off is changed, the voltage V
₁Independent of the voltage V supplied to the second load 34_TwoAdd
(V₁> V _TwoAlso V₁<V_Two
Is also possible).

As described above, in the present embodiment, the control circuit 41 controls the first transistor 27 and the second transistor 28 on and off in accordance with the status of whether the cord 22 is connected or not. , The current can be supplied to the second load 34 both when the cord 22 is connected and disconnected. Therefore, even in the cordless state where the cord 22 is removed, the hot water supply motor 33 can be operated to supply hot water. Further, even if the terminal voltage of power storage element 32 changes, the voltage of hot water supply motor 33 can be freely adjusted by the user, and the user can adjust the hot water supply speed to a desired value.

In the present embodiment, when the cord 22 is connected, charging of the storage element 32 or direct supply of current from the current supply circuit 25 to the hot water supply motor 33 is not required, and the heat retention heater 23 is used. Can be realized by, for example, providing a switch or the like between the input terminals or the output terminals of the rectifier circuit 26 and turning on the switch. Therefore, the temperature of the hot water stored in the heat retaining cylinder can be kept constant for a long time.

Next, an embodiment of the third means of the present invention will be described with reference to FIG. The switch 43 turns on and off the second load 34 as in the above embodiment. The second switch 46 switches between a voltage setting means 39 operated by the user and a voltage source 44 having the same value as when the setting of the voltage setting means 39 is maximized, and outputs this output signal to a control circuit. 45. In this embodiment, the switch 43 and the second switch 46 are interlocked with each other. When the switch 43 is on, the second switch 46 tilts to the side a to control the output of the voltage setting means 39. It is connected to a circuit 45. When the switch 43 is off, the second switch 4
6 is connected to the b side to connect the output of the voltage source 44 to the control circuit 45. A capacitor 42 is connected in parallel to a series circuit of the second load 34 and the switch 43.

The operation of the present embodiment will be described below with reference to FIG. FIG. 4 is a current waveform of a main part of the circuit of FIG. In a state where the cord 22 is not connected to the commercial AC power supply 21 and a state where the cord 22 is connected to the commercial AC power supply 21 and the switch 43 is turned on, the circuit of the present embodiment operates in the same manner as the above-described embodiment. The description is omitted.

When the cord 22 is connected and the hot water supply operation is not performed, that is, when the switch 43 is turned off, the voltage source 44 is connected to the control circuit 45 by the second switch 46. Things. Accordingly, the control circuit 45 determines that the voltage across the second load 34 is
Thus, the duty ratio of the second transistor 28 is controlled by operating in the same manner as in the above-described embodiment so that the value becomes substantially set. Therefore, during the period when the second transistor 28 is on, the electric storage element 32
It is charged by a current flowing from the current supply circuit 25 and the capacitor 42 shown in FIG. ₁ via the second transistor 28 and the choke coil 31. (I _{2 in} FIG. 4 indicates the current flowing out of the capacitor 42.) While the second transistor 28 is off, the storage element 32 is connected to the storage element from the choke coil 31 shown in I ₃ in FIG. 32. A circulating current flowing through the first reverse conducting diode 29 flows. Therefore, the total charging current I ₄ becomes I ₄ = I ₁ + I ₂ + I _3. This is an operation as a so-called step-down chopper. Therefore, if the voltage setting between both ends of the second load 34 is increased by the voltage source 44, The more the power is supplied from the choke coil 31, the higher the charging current can be, which is higher than the current supplied by the current supply circuit 25.

That is, according to the present embodiment, the charging time of the electric storage element 32 can be shortened. In the embodiment of the second means of the present invention, the variable resistor 40 constituting the voltage setting means 39 is returned to the minimum value when the user finishes the hot water supply operation. The output voltage at 39 also has a small value. Therefore, the charging time of the storage element 12 is considerably longer than that of the present embodiment.

As described above, according to this embodiment, in addition to the effects of the above-described embodiment, the charging time of the electric storage element 32 can be reduced, and the user can supply hot water at any time.

Next, an embodiment of the fourth means of the present invention will be described with reference to FIG. In the present embodiment, the third switch 4 interlocked with the switch 43 and the second switch 46
7 is provided. In other words, when the switch 43 is on, the third switch 47 operates to transmit the voltage between both ends of the second load 34 to the voltage detecting means 38 by leaning to the side b, and when the switch 43 is off, a It operates to transmit the voltage between both ends of the series circuit of the first transistor 27 and the second transistor 28 to the voltage detecting means 38 by leaning to the side.

The operation of this embodiment will be described below. In a state where the commercial AC power supply 21 is not connected, the circuit of the present embodiment operates in the same manner as the embodiment of the second means, and a description thereof will be omitted.

When the commercial AC power supply 21 is connected and the user operates the switch 43 to turn it on, the third switch 47 is connected to the b side. Therefore, the voltage detecting means 38 detects the voltage across the second load 34. At the same time, the second switch 46 tilts to the a side and transmits the voltage set in the voltage setting means 39 to the control circuit 48. The control circuit 48 adjusts the duty ratio of the second transistor 28 so that the voltage across the second load 34 and the value of the voltage setting means 39 become equal.

When the switch 43 is off, the third switch 47 is connected to the side a. Therefore, the voltage detecting means 38 always detects the voltage across the series circuit of the first transistor 27 and the second transistor 28. At this time, the second switch 46 simultaneously falls to the b side,
The voltage of the voltage source 44 is transmitted to the control circuit 48. Therefore, the control circuit 48 adjusts the duty ratio of the second transistor 28 so that the output of the voltage source 44 and the voltage across the series circuit of the first transistor 27 and the second transistor 28 become equal. . In this case, the value of the voltage source 44 is a value obtained by adding the voltage at the time of completion of the charging of the storage element 32 to the same value as when the setting of the voltage setting means 39 is maximized. Therefore, in a state where the charging of the storage element 32 has not progressed much, a larger charging current can be supplied to the storage element than in the embodiment of the third means of the present invention.
That is, according to the present embodiment, a cordless device that requires a shorter charging time is realized.

Next, an embodiment of the fifth means of the present invention will be described with reference to FIG. In this embodiment, a detecting means 50 for detecting a power failure of a commercial AC power supply, and a diode 5 connected between the rectifier circuit 26 and the second transistor 28
1 is provided.

The operation of this embodiment will be described below. The state in which the commercial AC power supply 21 is connected by the cord 22 and the electric storage element 32 is charged, and the state in which the commercial AC power supply 21 is not connected and the electric charge of the electric storage element 32 is used to supply a current to the second load 34. The supplying state is the same as that of the second embodiment of the present invention.

When the commercial AC power supply 21 is out of power, the detecting means 50 monitors the voltage of the anode of the diode 51.
To communicate. Upon receiving this information, the control circuit 49 immediately stops driving the second transistor 28. At this time, if the user turns on the switch 36 to perform the hot water supply operation, the driving of the first transistor 27 is started immediately.

In FIG. 7, I ₁₀ is a current flowing from the power storage element 32 while the first transistor 27 is on, and I ₁₁ is a current flowing through the choke coil 31. This choke coil 3
Even if the first transistor 27 is turned off, the current I ₁₁ flowing to 1 does not suddenly become zero due to the magnetic energy stored therein, but flows through the second reverse conducting diode 30. , To the second load 34 as I ₁₂ .

As described above, according to the present embodiment, the second load 34 can be driven without any trouble by driving the first transistor 27 even if a power failure occurs.

Next, an embodiment of the sixth means of the present invention will be described with reference to FIG.
It will be described based on. In the present embodiment, the conduction ratio limiting means 52 for keeping the conduction ratio of the first transistor 27 at 85% or less is provided. This conduction ratio limiting means 52
Is connected to the control circuit 53.

Hereinafter, the operation of this embodiment will be described. The operation in a state where the cord 22 is connected is the same as in the above embodiments. When the hot water supply operation is being performed with the cord 22 removed, that is, when the switch 36 is turned on, the control circuit 53 is operated in the same manner as in the previous embodiment.
Performs negative feedback control on the conduction ratio of the first transistor 27 so that the output value of the voltage detecting means 38 and the output of the voltage setting means 39 become equal. However, in this embodiment, when the duty ratio of the first transistor 27 is about to exceed a predetermined value (85%), the duty ratio limiting means 52 operates, and the control circuit 53 sends the first transistor 27 85
%. by this,
The conduction ratio of the first transistor 27 is limited to 85% at the maximum, and the peak value or the effective value of the current or the like flowing through the first transistor 27, the second reverse conduction diode 30, the choke coil 31, and the storage element 32. Is kept below a certain value. Therefore, according to the present embodiment, it is possible to use those elements having a small current rating, and also to reduce the amount of heat generated so that malfunction or destruction due to heat does not occur.

Further, according to the present embodiment, in a general boost chopper circuit, a phenomenon occurs in which the output decreases due to an increase in circuit loss due to an increase in the conduction ratio of the transistor.
In this embodiment, since the conduction ratio limiting means 52 is provided,
The negative feedback operation can be performed after excluding the conduction ratio range where such a phenomenon occurs. That is,
Control stability can also be ensured.

In each of the above embodiments, the first transistor 27 is connected to the negative side of the rectifier circuit 26, and the second transistor 28 is connected to the positive side. Not that. Even if the first transistor 27 is connected to the plus side and the second transistor 28 is connected to the minus side, the effect is exactly the same. Further, although both the first transistor 27 and the second transistor 28 use NPN transistors, the same effect can be obtained by using PNP transistors, MOSFETs, or the like.

As the first load 24, the heater 2 for keeping heat is used.
Although 3 was used, this is not necessarily required to be in accordance with this configuration. In short, when a voltage having a voltage difference between the voltage of the commercial AC power supply 21 and the voltage of the power storage element 32 is applied, a charging current of an appropriate magnitude is supplied to the power storage element 32 or a necessary current is supplied to the second load 34. Anything that can be done. In addition, although the hot water supply motor 33 is used for the second load, any hot water supply motor may be used even in a cordless state.

Regarding the conditions for use, as in each of the above embodiments, the cords may be used in a connected state, or may be used only in a cordless state such as outdoor equipment. There may be.

Further, each of the above embodiments may be used in an appropriately combined configuration. For example, a negative feedback operation by the control circuit is performed both when the cord is connected and when the cord is cordless. When the cord is attached, the duty ratio of the second transistor 28 is controlled. If the conduction ratio is controlled, in any state, the voltage of the second load can be freely adjusted by the setting of the user, making the cordless device very easy to use. It is. When charging with a cord, the second switch 4
If a negative feedback operation of the control circuit is performed by providing 6 and tilting it to the b side, short-time charging of the storage element can be realized, and higher performance can be achieved.

[0055]

The first means of the present invention is to provide a current supply circuit comprising a detachable commercial AC power supply and a first load, a rectifier circuit connected to the current supply circuit, and an output of the rectifier circuit. A series circuit of a connected first transistor and a second transistor, a first reverse conducting diode connected between the collector and the emitter of the first transistor, and a collector and an emitter of the second transistor. Connected second reverse conducting diode, a series circuit of a choke coil and a storage element connected between the collector and the emitter of the first transistor, and controlling on / off of the first transistor and the second transistor And a second load connected between a connection point of the choke coil and the storage element and a collector of the second transistor, and a switch operated by a user. A structure having a series circuit of a pitch, the conventionally required trans is unnecessary, and realizes a cordless equipment which attained miniaturization, weight and cost of the equipment.

The second means of the present invention, in addition to the structure of the first means of the present invention, detects the voltage across the series circuit of the second load and the switch and outputs the detected voltage to the control circuit. Voltage detection means, having a voltage setting means operated by the user, when the commercial AC power supply is connected, the control circuit controls the conduction ratio of the second transistor, and the output voltage of the voltage detection means As a configuration in which the output voltage of the voltage setting means is controlled to be equal, a cordless device that can always exhibit the performance of the device regardless of the degree of charge of the storage element is realized.

According to a third aspect of the present invention, in addition to the configuration of the second aspect of the present invention, there is provided a voltage source for generating a constant voltage and a second switch. Is turned off, the voltage setting means outputs the voltage on the voltage source side to the control circuit, thereby realizing a cordless device in which the charging time of the storage element is reduced.

Further, the fourth means of the present invention has, in particular, a third switch connected to the voltage detecting means, and the voltage detecting means switches the voltage across the second load when the switch is on. As a configuration for detecting the output voltage of the rectifier circuit when turned off, a cordless device that requires a short charging time is realized.

Further, the fifth means of the present invention comprises, in particular, a detecting means for detecting that the commercial AC power supply is not connected, and when the commercial AC power supply is not connected, the control circuit operates the first transistor. As a configuration for controlling the continuity ratio of the power supply to make the output voltage of the voltage detection means equal to the output voltage of the voltage setting means, a cordless device capable of operating the device even during a power failure is realized.

Further, the sixth means of the present invention has, in particular, a duty ratio limiting means for limiting the duty ratio of the first transistor, and the control circuit prevents the first transistor from exceeding a predetermined duty ratio. As a control structure, the first transistor can be prevented from being destroyed, and a cordless device with improved reliability can be realized.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a cordless device according to an embodiment of a first means of the present invention.

FIG. 2 is a circuit diagram of a cordless device according to an embodiment of the second means.

FIG. 3 is a circuit diagram of a cordless device according to an embodiment of the third means.

FIG. 4 is a waveform chart showing the operation of each unit.

FIG. 5 is a circuit diagram of a cordless device according to an embodiment of the fourth means.

FIG. 6 is a circuit diagram of a cordless device according to an embodiment of the fifth means.

FIG. 7 is a waveform chart showing the operation of each unit.

FIG. 8 is a circuit diagram of a cordless device according to an embodiment of the sixth means.

FIG. 9 is a circuit diagram of a cordless device according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Commercial AC power supply 24 First load 25 Current supply circuit 26 Rectifier circuit 27 First transistor 28 Second transistor 29 First reverse conducting diode 30 Second reverse conducting diode 31 Choke coil 32 Storage element 34 Second Load 35, 41, 45, 48, 49, 53 Control circuit 38 Voltage detection means 39 Voltage setting means 43 Switch 46 Second switch 47 Third switch 50 Detection means 51 Diode 52 Conduction ratio limiting means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-264010 (JP, A) JP-A-62-53124 (JP, A) JP-A-7-143679 (JP, A) 63419 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) H02J ⁷ /00-7/12 H02J 7/34-7/36 A47J 27/21 101

Claims (6)

(57) [Claims] 1. A current supply circuit including a detachable commercial AC power supply and a first load, a rectifier circuit connected to the current supply circuit, a first transistor and a second transistor connected to an output of the rectifier circuit. A series circuit of transistors, a first reverse conducting diode connected between the collector and the emitter of the first transistor, and a second reverse conducting diode connected between the collector and the emitter of the second transistor. A series circuit of a storage element and a choke coil connected between the collector and the emitter of the first transistor,
A control circuit that controls on / off of the first transistor and the second transistor, a second load and a user connected between a connection point of the choke coil and the storage element and a collector of the second transistor. A cordless device having a series circuit with a switch to be operated. 2. A commercial AC power supply, comprising: voltage detecting means for detecting a voltage between both ends of a series circuit of a second load and a switch and outputting the detected voltage to a control circuit; and voltage setting means operated by a user. 2. The cordless cordless control system according to claim 1, wherein the control circuit controls the conduction ratio of the second transistor so that the output voltage of the voltage detection means and the output voltage of the voltage setting means are equal when the power supply is connected. machine. 3. A voltage source for generating a constant voltage and a second switch, and when the switch is turned off in a state where a commercial AC power supply is connected, a voltage setting means supplies a voltage on the voltage source side to the control circuit. 3. The cordless device according to claim 2, wherein And a third switch connected to the voltage detecting means, wherein the voltage detecting means detects a voltage across the second load when the switch is on, and detects an output voltage of the rectifier circuit when the switch is off. The cordless device according to claim 2, wherein the cordless device detects. 5. A detecting means for detecting that a commercial AC power supply is not connected, and in a state where the commercial AC power supply is not connected, a control circuit controls a conduction ratio of the first transistor to detect a voltage. The cordless device according to any one of claims 2 to 4, wherein the output voltage of the means and the output voltage of the voltage setting means are controlled to be equal. 6. A method according to claim 2, further comprising a duty ratio limiting means for limiting the duty ratio of the first transistor, wherein the control circuit controls the first transistor so as not to exceed a predetermined duty ratio. Cordless equipment according to the paragraph.